The barrels use a multicrystallinesolar photovoltaic module mounted to the top of the barrel to collect energy from the sun and store it in a 12V battery. The barrels then turn the stored energy into compaction power using a 12V gear motor with a maintenance-free, sealed gear box and oversized brushes. “The energy density of the panel has become pretty important, and the multicrystalline panels that we are using offer a higher energy density, and that’s one of the reasons that we’ve stayed with them,” says Jeff Satwicz, product manager for the Big Belly.

The solar panels are protected by a Lexan polycarbonate cover, which domes over the top of the barrel. “The solar panels’ natural ruggedness wasn’t enough for us, so we needed to bump it up and protect it with a polycarbonate cover,” says Satwicz. The polycarbonate blocks out minimal amounts of the solar radiation necessary to power the compaction system, but the cost of leaving the panels susceptible to the elements is far greater than any power lost from the Lexan covering. Other materials used in the barrels are galvanized steel and thermoformed plastic parts.

The barrel has a monitoring system consisting of a microprocessor, circuit board and infrared emitter and sensor. This system determines when the trash needs to be compacted and collected. “The reason we went to a microprocessor is it allows us to do it in software; it allows us to do it very intelligently and using a minimum amount of energy,” says Satwicz. Once the light beam is broken, that information is sent to the microprocessor and circuit board, which then initiate the compaction cycle.

The infrared beam monitors the trash level periodically rather than constantly so trash passing by during disposals doesn’t trigger a preemptive compaction cycle. But the more trash deposited, the more frequently the cycles of compaction have to run. “You can imagine the scenario that the bin has just been emptied, it’s going to take quite some time for the bin to fill up again and then break the eye (infrared beam), it might take 20 or 30 times of people throwing away trash,” says Satwicz “but then once it’s broken, you may need to run a cycle every one or two times that someone throws away trash.”

On the outside of the barrels are light meters to display fullness, represented by green, yellow and red surface-mount LEDs. The meter “will go from green, meaning it’s good and good to go, to yellow, meaning it’s really time to come pick it up and eventually they’ll hit red when the machine has become overfull and is really past its capacity,” says Satwicz.

According to Satwicz, there is no risk of injury when empting the barrels because “all the doors in the machine are safety interlocked so that the motor cannot run if the doors are open.” They are also both CE- and RoHS-compliant. “The entire machine is RoHS compliant, from the electronics to the fasteners to the metal we use. We did it primarily so that we could sell the machine in Europe and also because we feel it’s an important environmental stance to take.”

The aesthetic importance of these barrels is that they don’t look much different than standard, non-compacting barrels and therefore don’t attract unneeded attention. “We really just want it to blend into the environment and be the type of thing that you see when you want to throw away trash,” says Satwicz, “and just kind of disappears into the environment when you’re not looking for a trashcan.”

Seahorse has plans to continue development on the existing Big Belly model. “One of the next things that we’re going to do is make these Big Bellys be able to communicate information wirelessly to us and our customers,” says Bruce Todtfeld, vice president of marketing for Seahorse. “Our customers are very interested in understanding what the fullness situation of a machine is, so they can create an optimal route and only pick up those cans that need to be picked up and not pick up those cans that don’t need to be picked up.” Seahorse already has one new design slated for September 2007, and is working on a dumpster-sized compaction system.

Industrial workplaces are governed by OSHA rules, but this isn’t to say that rules are always followed. While injuries happen on production floors for a variety of reasons, of the top 10 OSHA rules that are most often ignored in industrial settings, two directly involve machine design: lockout/tagout procedures (LO/TO) and machine guarding.

Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.